TY  - CHAP
A1  - Auel, C.
A1  - Hagemann, M.
A1  - Albayrak, I.
A1  - Boes, R.M.
T1  - Optimizing the sustainability of sediment bypass tunnels to counter reservoir sedimentation
T2  - Proc. 25th ICOLD Congress, Q99 R31, Stavanger, Norway
N2  - In order to prevent reservoir sedimentation, sediment bypass tunnels can be an efficient countermeasure restoring sediment continuity of impounded rivers. Although supercritical open channel flow conditions in these tunnelsprevent tun-nel blockage, in combination with the high bypassed sediment volume it may lead tosevere abrasion damages on inverts. Consequently,wear termed hydroabra-sionoccurs. Based on laboratoryexperiments, a theoretical model was devel-oped to predict abrasion rates and service life timeof sediment bypass tunnels. Insituexperiments are further conducted for model calibration to provide an abrasion prediction approach for field applications.Finally,recommendations concerning the hydraulic design of the tunnel as well as the structural design ofthe invertareprovided.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151518
SP  - 431
EP  - 452
PB  - ICOLD
ER  - 
TY  - CHAP
A1  - Auel, C.
A1  - Albayrak, I.
A1  - Sumi, T.
A1  - Boes, R.M.
T1  - Saltation-abrasion model for hydraulic structures
T2  - Proc. 1st Int. Workshop on Sediment Bypass Tunnels, VAW Mitteilungen 232
N2  - The derivation of an abrasion prediction model for concrete hydraulic structures valid in supercritical flows is presented herein. The state of the art saltation-abrasion model from Sklar and Dietrich (2004) is modified using the findings of a recent research pro-ject on the design and layout of sediment bypass tunnels. The model correlates the im-pacting parameters with the invert material properties by an abrasion coefficient kv. The value of this coefficient is verified by a similarity analysis to bedrock abrasion in river systems applying a correlation between the abrasion rate and the bed material strength. A sensitivity analysis reveals that the saltation-abrasion model is highly dependent on an adequate estimation of kv. However, as a first order estimate the proposed model en-ables the practical engineer to estimate abrasion at hydraulic structures prone to super-critical flows.
N2  - In diesem Beitrag wird ein Abrasionsvorhersagemodell für wasserbauliche Anlagen vorgestellt, die hohen Fliessgeschwindigkeiten ausgesetzt sind. Das Modell beruht auf dem Ansatz von Sklar und Dietrich (2004) und beinhaltet neue Erkenntnisse über die Partikeltrajektorien und Aufprallgeschwindigkeiten in schiessendem Abfluss. Das Mo-dell verbindet die Einwirkungs- mit den Materialwiderstandsparametern der Sohle mit Hilfe des Abrasionskoeffizienten kv. Der Wert dieses Koeffizienten wurde anhand einer Ähnlichkeitsanalyse zur Flusssohlenabrasion durch eine Korrelation der Abrasionsrate mit der Sohlmaterialfestigkeit verifiziert. Eine Sensitivitätsanalyse zeigt den grossen Einfluss dieses Parameters auf die Abrasion auf. Dennoch ist das vorgeschlagene Mo-dell als praktische Hilfe für den Ingenieur in der Praxis geeignet, um die Abrasion an wasserbaulichen Anlagen abzuschätzen
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151528
SP  - 101
EP  - 121
PB  - ETH Zurich
ER  - 
TY  - CHAP
A1  - Auel, C.
A1  - Boes, R.M.
A1  - Sumi, T.
T1  - Abrasion damage estimation of sediment bypass tunnels: Validation and comparison of two prediction models
T2  - Annuals of Disaster Prevention Research Institute 58B, Kyoto University, Japan
N2  - Abrasion damage estimation of sediment bypass tunnels: Validation and comparison of two prediction models. Annuals of Disaster Prevention Research Institute 58B, Kyoto Univer-sity, Japan
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151547
UR  - http://hdl.handle.net/2433/210040
SP  - 540
EP  - 549
PB  - Kyoto University
ER  - 
TY  - CHAP
A1  - Auel, C.
A1  - Albayrak, I.
A1  - Boes, R.M.
T1  - Bed-load particle motion in supercritical open channel flows
T2  - Proc. 36th IAHR World Congress, Delft - The Hague, the Netherlands
N2  - Supercritical sediment-laden open channel flows occur in many hydraulic structures including dam outlets, weirs, and bypass tunnels. Due to high flow velocities and sediment flux severe problems such as erosion and abrasion damages are expected in these structures (Jacobs et al., 2001). Sediment bypass tunnels (SBT), as an effective measure to decrease reservoir sedimentation by bypassing sediments during floods, are exceptionally prone to high abrasion causing significant annual maintenance cost (Sumi et al., 2004; Auel and Boes, 2011). The Laboratory of Hydraulics, Hydrology and Glaciology (VAW) of ETH Zurich conducted a laboratory study to counteract these negative effects (Auel, 2014). The main goals of the project were to analyze the fundamental physical processes in supercritical flows as present in SBTs by investigating the mean and turbulence flow characteristics (Auel et al., 2014a), particle motion (Auel et al., 2014b; 2015b), and abrasion development caused by transported sediment. Besides new insights into the three listed topics, paramount interest is given to their inter-relations and the development of an easily applicable abrasion prediction model (Auel et al., 2015a). This paper presents selected results on the second topic, i.e. the analysis of saltation trajectories of single coarse particles in supercritical flow.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-151559
PB  - IAHR
ER  -